> Most H1B immigrants
There are no H-1B immigrants.
There may be H-1B holders who plan to become immigrants, but H-1B is a nonimmigrant work visa.
> Now all these immigrants have learned your language, passed job interviews, and are competing to come to your country to give you 1$M and help your economy.
No, they are competing to come and reduce the market clearing cost of labor and increase the returns to capital in our economy. Which is good for you if you are (1) one of the incoming laborers, or (2) a person whose main interaction with the US economy is via capital investment, not labor income.
> To those who say we must invest in local workforce, I wonder why would you have to stop immigration to start investing in local workforce?
You don't have to stop immigration.
You do, on the other hand, need to stop importing labor in a manner specifically and selectively designed to avoid upward pressure on wages (and thereby, stop the incentive to develop domestic supply) for high-skill, high-demand positions and to terminate temporary residency when it no longer serves that purpose.
Or, you need to better capture the returns produced by those means and direct them to domestic workforce development.
I'm one of the most pro-immigrant and pro-immigration and anti-Trump, people you’ll find, and I would shed not a single tear if Trump managed to permanently kill, rather than merely temporarily suspend, the H-1B program.